RpoS protein

Examples of RpoS protein in the following topics:

• Regulation of Sigma Factor Translation

  • The most commonly studied sigma factors are often referred to as a RpoS proteins as the rpoS genes encode for sigma proteins of various sizes.
  • Using RpoS proteins as the focus, the RpoS expression and transcription is regulated at the translational level.
  • Small noncoding RNAs are able to sense environmental changes and stresses resulting in increased expression of RpoS protein.
  • The resultant increase of RpoS protein is based on the cellular environment and its needs.
  • These RNAs can induce activation of rpoS translation.

• Small Regulatory RNAs

  • The mechanisms by which small regulatory RNAs function include binding to protein targets, protein modification, binding to mRNA targets, and regulating gene expression .
  • Antisense RNAs are used to bind to complementary mRNAs and inhibit protein translation.
  • RPoS genes specifically encode for sigma factors which function as regulators of transcription and stress responses.
  • Small RNAs have been shown to regulate RPoS translation and those identified thus far include: DsrA, RprA, and OxyS.
  • These RNAs can either activate or inhibit RPoS translation.

• Verrucomicrobia

  • Support for this superphylum has been found by examining the RNA polymerase protein RpoB.
  • rpoB is the gene that encodes the β subunit of bacterial RNA polymerase.
  • This protein has a unique 3 amino acid insert in all sequenced Chlamydiae, Lentisphaerae and Verrucomicrobia species.
  • This protein is absent in the Poribacteria.
  • On the single circular chromosome, 2473 predicted proteins were found, 731 of which had no detectable homologs.

• Purifying Proteins by Affinity Tag

  • Protein tags are peptide sequences genetically grafted onto a recombinant protein.
  • Protein tags are peptide sequences genetically grafted onto a recombinant protein.
  • These include chitin binding protein (CBP), maltose binding protein (MBP), and glutathione-S-transferase (GST).
  • BCCP (Biotin Carboxyl Carrier Protein), a protein domain recognized by streptavidin
  • Green fluorescent protein-tag, a protein which is spontaneously fluorescent and can be bound by nanobodies

• Ribosomes

  • The purpose of the ribosome is to translate messenger RNA (mRNA) into proteins with the aid of tRNA.
  • Ribosomes are tiny spherical organelles that make proteins by joining amino acids together.
  • Proteins synthesized in each of these locations serve a different role in the cell.
  • All prokaryotes have 70S (where S=Svedberg units) ribosomes while eukaryotes contain larger 80S ribosomes in their cytosol.
  • The ribosome assembles amino acids into a protein.

• Group Translocation

  • Proteins may be incorporated into the plasma membrane.
  • In addition, bacteria may target proteins into or across the outer membrane.
  • A specialized enzyme, sortase, cleaves the target protein at a characteristic recognition site near the protein C-terminus, such as an LPXTG motif (where X can be any amino acid), then transfers the protein onto the cell wall.
  • The PGF-CTERM/archaeosortase A system in archaea is related to S-layer production.
  • A fifth Tat protein TatE that is homologous to the TatA protein is present at a much lower level in the cell than TatA.

• ABC Transporters

  • ABC transporters are a protein superfamily that all have an ATP binding cassette and transport substances across membranes.
  • Proteins are classified as ABC transporters based on the sequence and organization of their ATP-binding cassette (ABC) domain(s).
  • The third subgroup of ABC proteins do not function as transporters, but rather are involved in translation and DNA repair processes.
  • In bacterial efflux systems, certain substances that need to be extruded from the cell include surface components of the bacterial cell (e.g. capsular polysaccharides, lipopolysaccharides, and teichoic acid), proteins involved in bacterial pathogenesis (e.g. hemolysis, heme-binding protein, and alkaline protease), heme, hydrolytic enzymes, S-layer proteins, competence factors, toxins, antibiotics, bacteriocins, peptide antibiotics, drugs and siderophores.
  • Summarize the function of the three major ABC transporter categories: in prokaryotes, in gram-negative bacteria and the subgroup of ABC proteins

• Damage to Proteins and Nucleic Acids

  • A bacteriostatic agent is a biological or chemical agent that stops bacteria from reproducing by targeting DNA replication and proteins.
  • Bacteriostatic antibiotics limit the growth of bacteria by interfering with bacterial protein production, DNA replication, or other aspects of bacterial cellular metabolism.
  • It is a protein synthesis inhibitor.

• Single-Stranded DNA Bacteriophages

  • They encode 4 to 11 proteins.
  • Members of the subfamily Gokushovirus have only two structural proteins: capsid proteins F (Virus Protein 1) and DNA pilot protein H (Virus Protein 2) and do not use scaffolding proteins.
  • These are formed by large insertion loops within the protein F of gokushoviruses and are absent in the microviruses.
  • They lack both the external scaffolding protein D and the major spike protein G of the species in the genus Microvirus.
  • Each virion has 60 copies each of the F, G, and J proteins and 12 copies of the H protein.

• Genetics and Regulation of N2 Fixation

  • Through control of gene expression, nitrogen fixing bacteria can turn on and off the proteins needed for nitrogen fixation.
  • If there is no need for N2 fixation, the production of proteins needed for fixation are tightly controlled.
  • Some of nif genes are: Nif A, D, L,K, F,H S,U,Y,W,Z .
  • Activation of nif genes transcription is done by the nitrogen sensitive NifA protein.
  • If there is a sufficient amount of reduced nitrogen or oxygen is present, another protein is activated, NifL.